The commercial spaceflight company Virgin Galactic flew its SpaceShipTwo space plane on the craft's first rocket-powered test flight Monday (April 29) from the Mojave Air and Space Port in California. But that's just the start of a campaign to launch paying passengers into space.

SpaceShipTwo is designed to carry space tourists on trips to the edge of space and back for $200,000 a ticket. While the price may be steep for some, more than 500 people have already put down deposits to ride. The first official passengers will be Virgin Galactic founder Sir Richard Branson and his family. SPACE.com spoke to the British billionaire just hours after the successful test flight Monday. Here's Branson's view of the landmark SpaceShipTwo flight:

Virgin Galactic wants to fly passengers on SpaceShipTwo at $250,00 a ticket. Would you go if you could?

Richard Branson: Magnificent! We had the biggest grins on our faces that we've had for a long, long time. Today was the biggest milestone in this program. Now that we've broken the sound barrier, the flight was smooth, the rocket and spaceship can work together, we really feel that we're on our way. Over the next few months we'll go from Mach 1 to Mach 1.5 to Mach 2 to Mach 2.5 to Mach 3 to Mach 3.5 and then we'll be ready for space travel. [Photos: See SpaceShipTwo's 1st Powered Flight Test]

SPACE.com: That's quite a lot of test flights!

Branson: The most important thing if you a have a commercial spaceship company is we'll do as many test flights as is necessary to know we have a 100-percent safe program, and that’s why we want to put in as many flights as possible before we take people up there.

SPACE.com: What are you most looking forward to about flying on SpaceShipTwo?

Branson: I think it's just the ridiculous idea that you've built your own spaceship and you're going to space with your children. Being able to share something like this with them is, I think, a lot of fathers' dream. It's incredible that that dream will come true.

SPACE.com: You were there at Mojave today to watch the test flight. How big was the crowd, and what was the mood like?

Branson: It was meant to be a secret but I think word had gotten out, so we had a good crowd. All the 500 people who'd been instrumental in building the rockets and building the craft were there. Incredibly exhilarating. We had a beautiful view of the flight with the rocket roaring above us and the sound barrier being broken and the spaceship speeding up, so it couldn't have been more beautiful.

Frame from SpaceShipTwo Boom Camera during first rocket-powered flight on April 29, 2013.Credit: Virgin Galactic

Branson: 100-percent so. It was smooth. I think Mark and Mike, who were piloting the craft, were tempted just to carry on burning and go all the way into space. But they felt they might not have had a job when they got back down again. But it went great.

SPACE.com: When will the first trip to space be?

Branson: The last quarter of this year, so we're not too many months away. We'll do lots and lots of test flights between now and then, and we'll be up and away into space in the last quarter of this year.

SPACE.com: Would you be ready to ride SpaceShipTwo today, if you could?

Branson: If they would let me in, I'd be there like a shot.

SPACE.com: Do you expect today's flight to increase interest among potential customers?

Branson: Of course. I think there are millions of people out there who'd love to fly once they know there's a spaceship to fly in. We can now safely say that the end of this year we'll have a spaceship ready and waiting for them.

SPACE.com: What milestones should we look out for in the near future?

Branson: I think it's just speeding it up. The biggest one was to do Mach 1 with the spaceship and know that the two marry up well. Going from Mach 1 to Mach 3.5, 4, should be relatively easy. But it still hasn't been done and we need to test the spaceship and the rocket together to make sure it performs well, but we're confident it will.

Clara Moskowitz

Clara has been SPACE.com's Assistant Managing Editor since 2011, and has been writing for SPACE.com and LiveScience since 2008. Clara has a bachelor's degree in astronomy and physics from Wesleyan University, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what her latest project is, you can follow Clara on Google+.